Detection of cathepsin G mRNA transcripts in CD34⁺ CML blast cells. Total RNA was extracted from CD34⁺ CML blast cells. Ethidium bromide-stained gel of RT-PCR products. Lane 1 (left to right), molecular weight standard; lanes 2 and 5, CD34⁺ CML blast cells; lanes 3 and 6, normal CD34⁺ cells; lanes 4 and 7, breast cancer cell line as a negative control. Lanes 2 through 4 are RT-PCR products after amplification with cathepsin G primer set. Lanes 5 through 7 are RT-PCR products after amplification with β-actin primers and serve as a control.